This invention generally relates to a system for moving a seal away from a movable window when the movable window is in motion. This invention can be used with any movable window, but is preferably used with movable automotive windows. Further, this invention can be used with manual window systems, but is preferably used with automatic window systems.
Windows in vehicles typically have seals. It is an object of the automotive industry to reduce wind noise in the vehicle while the vehicle is in motion. Another object of the automotive industry is to reduce water from leaking into the vehicle around the windows.
One way to achieve these goals is to increase the force that the seal exerts on the window. The increased seal force reduces wind noise and prevents water from leaking around the seal. However, increasing the seal force on the window exaggerates several other difficulties encountered with movable window systems.
Automatic windows are designed to stop if they encounter an obstruction while being driven upwardly to close. It is necessary, but difficult, to differentiate the forces applied to the window to determine when an obstruction is encountered. Two categories of forces encountered by the window could be identified as normal or expected forces and foreign forces.
Typically, an obstruction is identified if the forces exerted on the window exceed a preselected threshold value. The preselected threshold value ideally represents the normal or expected forces encountered by the window system, including, but not limited to, the force exerted by the seal on the window.
However, these normal or expected forces are variable. For instance, the force exerted by the seal on the window varies with the temperature and the age of the seal. The force is higher at colder temperatures and when the seal is newer. Alternatively, the force decreases as the temperature rises and the seal ages.
The determination of an obstruction is made more difficult due to the varying expected forces encountered by the window system. Further, this difficulty is compounded by the increased window seal force, which results in a wider range of variation in seal force.
The differentiation of forces encountered by the window (i.e., expected forces v. foreign forces) would be greatly simplified if variable expected forces could be eliminated from the determination.
In general terms, this invention is an adjustable window seal assembly. The assembly can be used on any movable window, but is used preferably on automatically movable automotive windows. The adjustable window seal assembly operatively engages the movable window. The seal assembly engages the movable window when the movable window is stationary and has a reduced engagement force when the movable window is in motion.
The seal assembly consists of a stationary frame, a movable lip, and a cavity disposed between the stationary frame and the movable lip. These three elements are preferably formed as one piece of rubber. Three different scenarios as outlined below are disclosed to control the movement of the movable lip. Other embodiments are possible and within the broad teachings of this invention.
In one embodiment, the system also includes an air source, a valve and an electronic controller. When the electronic controller receives a signal that the window is about to begin moving, the electronic controller signals to the air source to start pumping air into the cavity through a valve. As the cavity fills with air, the movable lip is pulled away from the window thus reducing the seal force exerted on the window. When the electronic controller receives a signal that the window has stopped moving, the electronic controller signals to the air source to cease pumping air into the cavity. The valve is positioned to allow the air to escape from the cavity, thus forcing the cavity to collapse. Collapsing the cavity pushes the movable lip toward the window until the lip is biased against the window and the seal force is reapplied.
Alternatively, the system includes a vacuum pump, a valve and an electronic controller. When the electronic controller receives a signal that the window is about to begin moving, the electronic controller signals to the vacuum pump to start pumping air out of the cavity through a valve. In this embodiment, the stationary frame and the movable lip are configured such that as air evacuates from the cavity, the cavity collapses and the movable lip is pulled away from the window. As a result the seal force exerted on the window reduces. When the electronic controller receives a signal that the window has stopped moving, the electronic controller signals to the vacuum pump to cease pumping air out of the cavity. The valve is positioned to allow the air to reenter the cavity, thus forcing the cavity to expand. Expanding the cavity pushes the movable lip toward the window until the lip is biased against the window and the seal force is reapplied.
In another alternative, the system includes a voltage source and an electronic controller. Also, the rubber used to form the stationary frame, movable lip, and cavity is conductive rubber. When the electronic controller receives a signal that the window is about to begin moving, the electronic controller signals to the voltage source to apply a voltage to the seal assembly. In this embodiment, the stationary frame and the movable lip are configured similar to the vacuum system described above. In other words, as the voltage is applied the rubber becomes charged and creates an electric field that attracts the movable lip to the stationary frame, thus pulling the movable lip away from the window. As a result the seal force exerted on the window reduces. When the electronic controller receives a signal that the window has stopped moving, the electronic controller signals to the voltage source to cease applying a charge. The electric field is removed, thus forcing the movable lip toward the window until the lip is biased against the window and the seal force is reapplied.
This window seal system is advantageous because the seal force can be increased when the window is stationary, which reduces wind noise when the vehicle is in motion and also helps prevent water from leaking into the vehicle around the windows. Further, a smaller motor can be used to power the movement of the window because the motor has fewer forces to overcome.